Rock drills are normally powered by compressed air delivered by a plurality of hoses into various chambers for effecting the hammering of a so-called "striking bar" and a rifling arrangement with rachet and pawl assembly to rotate the striking bar when hammering occurs.
Recently developed rock drills have utilized an independent means of rotating the striking bar and a valveless piston control for hammering the striking bar, each powered and controlled by individually located hose connections through a series of elongated interior passageways. The elongated interior passageways do not provide the most efficient operation and the plurality of hose connections have proved to be inconvenient when it is necessary to remove the drill assembly from the drill rigging.